Type 2 vs Type 1: What's Actually Different
Reviewed by CDE Mehandi Sharma · Updated
Type 1 and Type 2 diabetes share a name and a symptom, but the reason behind them is completely different — and so is the treatment.
In Type 1 diabetes, the immune system attacks and destroys the cells that make insulin. The body ends up unable to produce insulin at all, so insulin injections are essential from the day of diagnosis and for life. It usually appears in childhood or early adulthood, and symptoms build over weeks.
In Type 2 diabetes, the body still makes insulin but cannot use it properly, and production slowly declines. It develops over years, usually in adults, and is managed with changes to food and activity, tablets, and sometimes insulin later on.
| Type 1 | Type 2 | |
|---|---|---|
| Cause | Immune system destroys insulin-making cells | Body resists insulin; supply falls over time |
| How fast it starts | Weeks | Years |
| Usual age | Childhood or early adulthood | Adults, though increasingly younger |
| Insulin needed | Always, from diagnosis | Sometimes, often years later |
| Can go into remission | No | Sometimes |
One thing worth saying plainly: nothing about diet or lifestyle causes Type 1 diabetes.
And one caution. An adult newly developing Type 1 can look like Type 2 at first, and be treated as Type 2 for years. If you are lean, have autoimmune conditions in the family, or your tablets stopped working unusually quickly, it is reasonable to ask your doctor whether your type has been confirmed.